This project is directed at the isolation, purification and characterization of virus-induced membrane antigens (MA) from cells infected with or transformed by Epstein-Barr virus (EBV) or Herpesvirus saimir (HVS). Antigens were successfully solubilized from cells infected with these viruses by treatment with papain. Antisera prepared against papain extracts contained neutralizing and anti-MA specific for each virus providing further evidence that MA was also expressed in the envelopes of each of these viruses. Trition-X 100 solubilization of EBV-infected cells followed by immune precipitation and analysis by polyacrylamide gel electrophoresis revealed 3 major glycoproteins and 1 major protein the membranes of such cells. Similarly, two major proteins have been isolated from cells infected with HVS. Studies are now ongoing to (1) determine whether other glycoproteins can be identified in cells infected with each virus; (2) determine whether the HVS proteins are glycoproteins; (3) determine whether individuals infected with EBV respond differently to the major glycoproteins, and (4) to isolate the major components to determine their relationship to each other and to define the components capable of inducing neutralizing antibodies against each virus.